A. Synthetically Prepared Fats
U.S. Pat. No. RE. 28,737 to Yetter, reissued Mar. 16, 1976, discloses the esterification of 1,3-diglycerides with oleic anhydride using trifluoromethane sulfonic acid as the catalyst. Example 1 discloses a synthetic cocoa butter prepared by oleic anhydride esterification of a 1,3-diglyceride component containing 45%, 1,3-palmitostearin, 42% 1,3-distearin and 11% 1,3-dipalmitin. Example 2 discloses the esterification of 1,3-dipalmitin with oleic anhydride to obtain a fat containing 90-95% oleic acid at the 2-position.
U.S. Pat. No. 3,492,130 to Harwood, issued Jan. 27, 1970, discloses hard butter compositions stable in the beta crystalline form prepared from a mixture of 60-95% SUS triglycerides and 40-5% of an equal amount of SUU and SSU triglycerides. These hard butter compositions can be used as extenders or substitutes for cocoa butter. Examples of such compositions are shown in Table 1 and were prepared by appropriate mixing of POP (Example 2), POO (Example 4), and PPO (Example 5) fats. See in particular compositions No. 1 (100% POP fat) and No. 5 (90% POP, 5% POO and 5% PPO fats). According to this patent, the data in Table II would show that Composition No. 5 is a suitable hard butter while composition No. 1 is not.
European patent application No. 23,062 to Cotton et al., published Jan. 28, 1981, discloses a hard butter fat suitable for replacing 100% of the added cocoa butter in chocolate formulations. This hard butter comprises 75-90% SUS triglycerides and less than 13% combined SSU and SUU triglycerides with an St:P ratio of from 1:1 to 2:1. Example 2 discloses one such hard butter containing 83% SUS, 4% SSO and 1% SOO triglycerides with an St:P ratio of 1.9.
B. Cocoa Butter Substitutes Derived From Fractionated Palm Oil and Cocoa Butter
Example 1 of U.S. Pat. No. 2,903,363 to Farr, issued Sept. 8, 1959, discloses the acetone fractionation of melted palm oil to obtain a fat suitable for chocolate coatings. In this process, a mixture of palm oil and acetone is held at 60.degree. F. to obtain a first set of crystals which are filtered off. The filtrate is then cooled to 30.degree. F. to obtain a second crop of fat crystals used in the chocolate coating. Example 5 discloses acetone fractionation of liquid cocoa butter by a similar process to provide a fat suitable for chocolate coatings.
British patent specification No. 827,172 to Best et al., published Feb. 3, 1960, discloses the preparation of cocoa butter substitutes by removing from palm oil at least 50% (preferably 60%) of a lower melting glyceride fraction, and by also preferably removing 5-15% of the highest melting glyceride fraction. Milk chocolates containing 31.8% (Example 9), 96% (Example 10), and 50% (Example 11) of such fractionated fats (based on total fat) are disclosed. U.S. Pat. No. 4,276,322 to Padley et al. issued June 30, 1981, discloses one such fractionated fat having 76.5% SUS triglycerides, 8.3% SUU triglycerides, 7.1% SSU triglycerides and 3.1% SSS triglycerides.
U.S. Pat. No. 3,093,480 to Arnold, issued June 11, 1963, discloses the preparation of cocoa butter substitutes by acetone extraction of palm oil. In the first set of extractions, the lower melting fraction of the fat is removed using acetone at temperatures between -5.degree. and 10.degree. C. The solid fat from this first extraction is subjected to a second set of extractions with acetone between 10.degree. and 35.degree. C. to remove higher melting triglycerides. Example 7 discloses chocolate made with this extracted fat at 27, 50 and 93% of the total fat.
Feuge et al., "Cocoa Butter-like Fats from Domestic Oils," J. Am. Oil Chem. Soc., Vol. 35, (1958), pp. 194-99, discloses the preparation of cocoa butter-like fats by esterifying glycerol with the respective fatty acids and then acetone fractionating the formed triglycerides. In this fractionation process, the triglycerides are dissolved in acetone and then held at 25.degree. C. with a precipitate (trisaturated fraction) being removed. The remaining solution is cooled to 0.degree. C. and the precipitate formed (monounsaturated fraction) removed to provide the cocoa butter substitute. Based on the melting characteristics of mixtures of these fats with cocoa butter, it was determined that the POP-type fat was the least compatible. Feuge et al. indicates that the probable cause of this incompatibility was the presence of certain isomers in the fat not found in cocoa butter.
C. Blends of Fractionated Palm Oil with StOSt/POSt Fats
U.S. Pat. No. 4,276,322 to Padley et al. issued June 30, 1981, discloses chocolate compositions containing hard fats formed by blending palm mid-fractions with StOSt/POSt fats. The StOSt/POSt fats consist of 80-98% StOSt and POSt triglycerides, less than 5% SSS triglycerides (other than PPP) and less than 5% PPP triglycerides (preferably less than 1% each of such triglycerides), less than 10% SSO triglycerides (other than PPO) and less than 3% PPO triglycerides (preferably less than 5% and more preferably less than 1% SSO triglycerides and preferably less than 1.5% PPO triglycerides), and less than 10% SOO triglycerides (preferably less than 5% of such triglycerides). See in particular POSt/palm mid-fraction blends disclosed at column 8, line 56 to column 9, line 32 of this patent. One such fat blend consisting of at least 40% POSt with the remainder being palm mid-fraction is disclosed to be useful at high levels in chocolate. Another such fat blend consisting of up to 50% palm mid-fraction with the remainder being POSt fat is disclosed as an excellent full fat replacer (can totally replace added cocoa butter) in the preparation of milk chocolate. See also U.S. Pat. No. 4,283,436 to Soeters et al. issued Aug. 31, 1981, which discloses similar hard fat replacers for chocolate.
U.S. Pat. No. 4,364,868 to Hargreaves, filed Feb. 2, 1981, issued Dec. 21, 1982, discloses "cocoa butter replacement" fats for chocolate compositions having certain proportions of POP/POSt/StOSt triglycerides defined by a ternary diagram. These fats can also contain up to 30%, preferably up to 20%, other triglycerides. These fats are typically formed by blending palm mid-fraction fats (preferably interesterified at the 1,3-positions using a lipase enzyme) with other fats such as cocoa butter and shea stearine. Examples 4-7 formed by blending cocoa butter with a palm mid-fraction (with or without subsequent interestification and fractionation) have POP/POSt/StOSt compositions of 45.6-47.1%/37.2-41%/12.4-16.8%. Example 8 discloses a fat (formed from stearic acid interestified with a palm mid-fraction) having POP/POSt/StOSt composition of 33.9%/47.7%/18.4% which is blended with a palm mid-fraction to provide a fat (Example 9) with POP/PSOt/StOSt composition of 44.7%/41.1%/14.2%. Example 11 discloses a fat formed by blending Shea stearine with a POP fat in a ratio of 70:30 (?) to obtain a fat having POP/POSt/StOSt composition of 75.7%/3.0%/21.3%. Other than the fat of Example 4, the fats of these Examples are disclosed as useful confectionery fats.